Analysis of dark line defects in the surface of cold-rolled sheet
WANG Ya-fen1��DU Hong-zhi2��ZHAO Guang-dong1
1. Automotive Sheet Research and Development Projects of Benxi Iron & Steel Co.�� Ltd.�� Benxi 117000�� China 2. Manufacturing?Department of Benxi Iron & Steel Co.��Ltd.�� Benxi 117000�� China
Abstract��The dark line defects on cold-rolled sheet were studied by field sampling and macroscopic examination. The surface of dark line defect positions was analyzed by scanning electron microscope and energy spectrum analysis. The reasons for the formation of dark line defects and the eliminating measures were discussed. The results indicated that the dark line defect on cold-rolled sheet was inclusion particle zone which was mainly composed of Al2O3. It was possible from the burrs on inner wall of the submerged nozzle in the process of continuous casting. Then�� the larger Al2O3 inclusions were crushed in subsequent rolling process and unevenly distributed on the iron matrix. However�� the tiny Al2O3 particles was not crushed and embedded in the matrix. The defects could be reduced or eliminated by adjusting the corresponding steelmaking process�� so as to improve the surface quality of cold-rolled sheet.
���Ƿң��ź�־���Թ㶫. ��������氵��ȱ�ݷ���[J]. �й������ڿ���, 2015, 33(3): 45-48.
WANG Ya-fen��DU Hong-zhi��ZHAO Guang-dong. Analysis of dark line defects in the surface of cold-rolled sheet. Chinese Journal of Iron and Steel, 2015, 33(3): 45-48.
2015, Vol. 33 
